Dynamic crack propagation across a perpendicular interface in a glass specimen was investigated to understand the interaction between the crack and the interface under impact loading. The glass specimen was composed of two glass plates in an edge-to-edge configuration with an adhesive layer in between. One of the plates had a notch for a plastic projectile to strike. A single crack developed from the notch tip, and propagated perpendicularly into the interface. The patterns of crack propagation across the interface depend on the adhesive conditions on the interface. Within a range of impact speeds, the crack is arrested at the interface without any adhesive. The crack passes across a firmly bonded interface with little obstruction by the interface. The crack branches into multiple cracks after it passes through a thicker interface filled with adhesive. Projectiles having higher kinetic energies cause more severe crack branching after the crack extends into the second glass plate.